X-Git-Url: http://nitlanguage.org

diff --git a/src/literal.nit b/src/literal.nit
index b4376a7..b183301 100644
--- a/src/literal.nit
+++ b/src/literal.nit
@@ -17,13 +17,10 @@
 # Parsing of literal values in the abstract syntax tree.
 module literal
 
-import parser
-import toolcontext
 import phase
 
-import modelbuilder #FIXME useless
-
 redef class ToolContext
+	# Parses literal values in the whole AST and produces errors if needed
 	var literal_phase: Phase = new LiteralPhase(self, null)
 end
 
@@ -48,11 +45,6 @@ private class LiteralVisitor
 
 	var toolcontext: ToolContext
 
-	init(toolcontext: ToolContext)
-	do
-		self.toolcontext = toolcontext
-	end
-
 	redef fun visit(n)
 	do
 		n.accept_literal(self)
@@ -64,12 +56,33 @@ redef class ANode
 	private fun accept_literal(v: LiteralVisitor) do end
 end
 
-redef class AIntExpr
-	# The value of the literal int once computed.
-	var value: nullable Int
-	redef fun accept_literal(v)
+redef class AExpr
+	# Get `self` as a `String`.
+	# Return null if not a string.
+	fun as_string: nullable String
 	do
-		self.value = self.n_number.text.to_i
+		if not self isa AStringFormExpr then return null
+		return self.value.as(not null)
+	end
+
+	# Get `self` as an `Int`.
+	# Return null if not an integer.
+	fun as_int: nullable Int
+	do
+		if not self isa AIntegerExpr then return null
+		return self.value.as(not null).to_i
+	end
+end
+
+redef class AIntegerExpr
+	# The value of the literal int once computed.
+	var value: nullable Numeric
+
+	redef fun accept_literal(v) do
+		value = n_integer.text.to_num
+		if value == null then
+			v.toolcontext.error(hot_location, "Error: invalid literal `{n_integer.text}`")
+		end
 	end
 end
 
@@ -89,10 +102,10 @@ redef class ACharExpr
 	do
 		var txt = self.n_char.text.unescape_nit
 		if txt.length != 3 then
-			v.toolcontext.error(self.hot_location, "Invalid character literal {txt}")
+			v.toolcontext.error(self.hot_location, "Syntax Error: invalid character literal `{txt}`.")
 			return
 		end
-		self.value = txt[1]
+		self.value = txt.chars[1]
 	end
 end
 
@@ -102,47 +115,13 @@ redef class AStringFormExpr
 	redef fun accept_literal(v)
 	do
 		var txt = self.n_string.text
-		var skip = 1
-		if txt[0] == txt[1] and txt.length >= 6 then skip = 3
-		self.value = txt.substring(skip, txt.length-(2*skip)).unescape_nit
-	end
-end
-
-redef class String
-	# Return a string where Nit escape sequences are transformed.
-	#
-	# Example:
-	#     var s = "\\n"
-	#     print s.length # -> 2
-	#     var u = s.unescape_nit
-	#     print s.length # -> 1
-	#     print s[0].ascii # -> 10 (the ASCII value of the "new line" character)
-	fun unescape_nit: String
-	do
-		var res = new Buffer.with_capacity(self.length)
-		var was_slash = false
-		for c in self do
-			if not was_slash then
-				if c == '\\' then
-					was_slash = true
-				else
-					res.add(c)
-				end
-				continue
-			end
-			was_slash = false
-			if c == 'n' then
-				res.add('\n')
-			else if c == 'r' then
-				res.add('\r')
-			else if c == 't' then
-				res.add('\t')
-			else if c == '0' then
-				res.add('\0')
-			else
-				res.add(c)
-			end
+		var behead = 1
+		var betail = 1
+		if txt.chars[0] == txt.chars[1] and txt.length >= 6 then
+			behead = 3
+			betail = 3
+			if txt.chars[0] == '"' and txt.chars[3] == '\n' then behead = 4 # ignore first \n in """
 		end
-		return res.to_s
+		self.value = txt.substring(behead, txt.length - behead - betail).unescape_nit
 	end
 end